feat: Allow setting of application name to the User-Agent header value

CHANGELOG.md

@@ -1,4 +1,11 @@
 ## [unreleased]
+### Features
+- [#358](https://github.com/influxdata/influxdb-client-go/pull/358):
+    - Added possibility to set an application name, which will be part of the User-Agent HTTP header
+        - Set using `Options.SetApplicationName`
+        - Error message is written to log if an application name is not set.
+    - Added example how to fully override `User-Agent` header using `Doer` interface
+
 ### Bug fixes
 - [#359](https://github.com/influxdata/influxdb-client-go/pull/359) `WriteAPIBlocking.Flush()` correctly returns nil error. 
 

api/http/options.go

@@ -23,6 +23,8 @@ type Options struct {
 	tlsConfig *tls.Config
 	// HTTP request timeout in sec. Default 20
 	httpRequestTimeout uint
+	// Application name in the User-Agent HTTP header string
+	appName string
 }
 
 // HTTPClient returns the http.Client that is configured to be used
@@ -119,6 +121,17 @@ func (o *Options) SetHTTPRequestTimeout(httpRequestTimeout uint) *Options {
 	return o
 }
 
+// ApplicationName returns application name used in the User-Agent HTTP header
+func (o *Options) ApplicationName() string {
+	return o.appName
+}
+
+// SetApplicationName sets an application name to the User-Agent HTTP header
+func (o *Options) SetApplicationName(appName string) *Options {
+	o.appName = appName
+	return o
+}
+
 // DefaultOptions returns Options object with default values
 func DefaultOptions() *Options {
 	return &Options{httpRequestTimeout: 20}

api/http/options_test.go

@@ -20,6 +20,7 @@ func TestDefaultOptions(t *testing.T) {
 	assert.Equal(t, uint(20), opts.HTTPRequestTimeout())
 	assert.NotNil(t, opts.HTTPClient())
 	assert.True(t, opts.OwnHTTPClient())
+	assert.EqualValues(t, "", opts.ApplicationName())
 }
 
 func TestOptionsSetting(t *testing.T) {
@@ -28,9 +29,11 @@ func TestOptionsSetting(t *testing.T) {
 	}
 	opts := http.DefaultOptions().
 		SetTLSConfig(tlsConfig).
-		SetHTTPRequestTimeout(50)
+		SetHTTPRequestTimeout(50).
+		SetApplicationName("Monitor/1.1")
 	assert.Equal(t, tlsConfig, opts.TLSConfig())
 	assert.Equal(t, uint(50), opts.HTTPRequestTimeout())
+	assert.EqualValues(t, "Monitor/1.1", opts.ApplicationName())
 	if client := opts.HTTPClient(); assert.NotNil(t, client) {
 		assert.Equal(t, 50*time.Second, client.Timeout)
 		assert.Equal(t, tlsConfig, client.Transport.(*nethttp.Transport).TLSClientConfig)

api/http/service.go

@@ -56,6 +56,7 @@ type service struct {
 	serverURL     string
 	authorization string
 	client        Doer
+	userAgent     string
 }
 
 // NewService creates instance of http Service with given parameters
@@ -73,6 +74,7 @@ func NewService(serverURL, authorization string, httpOptions *Options) Service {
 		serverURL:     serverURL,
 		authorization: authorization,
 		client:        httpOptions.HTTPDoer(),
+		userAgent:     http2.FormatUserAgent(httpOptions.ApplicationName()),
 	}
 }
 
@@ -128,7 +130,7 @@ func (s *service) DoHTTPRequestWithResponse(req *http.Request, requestCallback R
 		req.Header.Set("Authorization", s.authorization)
 	}
 	if req.Header.Get("User-Agent") == "" {
-		req.Header.Set("User-Agent", http2.UserAgent)
+		req.Header.Set("User-Agent", s.userAgent)
 	}
 	if requestCallback != nil {
 		requestCallback(req)

api/writeAPIBlocking.go

@@ -86,9 +86,8 @@ func (w *writeAPIBlocking) write(ctx context.Context, line string) error {
 		w.batch = append(w.batch, line)
 		if len(w.batch) == int(w.writeOptions.BatchSize()) {
 			return w.flush(ctx)
-		} else {
-			return nil
 		}
+		return nil
 	}
 	err := w.service.WriteBatch(ctx, iwrite.NewBatch(line, w.writeOptions.MaxRetryTime()))
 	if err != nil {

client.go

@@ -145,6 +145,9 @@ func NewClientWithOptions(serverURL string, authToken string, options *Options)
 		}
 		ilog.Infof("Using URL '%s'%s", serverURL, tokenStr)
 	}
+	if options.ApplicationName() == "" {
+		ilog.Error("Application name is not set")
+	}
 	return client
 }
 

client_test.go

@@ -7,11 +7,15 @@ package influxdb2
 import (
 	"context"
 	"fmt"
+	"log"
 	"net/http"
 	"net/http/httptest"
+	"runtime"
+	"strings"
 	"testing"
 	"time"
 
+	ihttp "github.com/influxdata/influxdb-client-go/v2/api/http"
 	"github.com/influxdata/influxdb-client-go/v2/domain"
 	http2 "github.com/influxdata/influxdb-client-go/v2/internal/http"
 	iwrite "github.com/influxdata/influxdb-client-go/v2/internal/write"
@@ -76,24 +80,76 @@ func TestWriteAPIManagement(t *testing.T) {
 	assert.Len(t, c.syncWriteAPIs, 0)
 }
 
+func TestUserAgentBase(t *testing.T) {
+	ua := fmt.Sprintf("influxdb-client-go/%s (%s; %s)", Version, runtime.GOOS, runtime.GOARCH)
+	assert.Equal(t, ua, http2.UserAgentBase)
+
+}
+
+type doer struct {
+	userAgent string
+	doer      ihttp.Doer
+}
+
+func (d *doer) Do(req *http.Request) (*http.Response, error) {
+	req.Header.Set("User-Agent", d.userAgent)
+	return d.doer.Do(req)
+}
+
 func TestUserAgent(t *testing.T) {
+	ua := http2.UserAgentBase
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		<-time.After(100 * time.Millisecond)
-		if r.Header.Get("User-Agent") == http2.UserAgent {
+		if r.Header.Get("User-Agent") == ua {
 			w.WriteHeader(http.StatusNoContent)
 		} else {
 			w.WriteHeader(http.StatusNotFound)
 		}
 	}))
 
 	defer server.Close()
+	var sb strings.Builder
+	log.SetOutput(&sb)
+	log.SetFlags(0)
 	c := NewClient(server.URL, "x")
+	assert.True(t, strings.Contains(sb.String(), "Application name is not set"))
 	up, err := c.Ping(context.Background())
 	require.NoError(t, err)
 	assert.True(t, up)
 
 	err = c.WriteAPIBlocking("o", "b").WriteRecord(context.Background(), "a,a=a a=1i")
 	assert.NoError(t, err)
+
+	c.Close()
+	sb.Reset()
+	// Test setting application  name
+	c = NewClientWithOptions(server.URL, "x", DefaultOptions().SetApplicationName("Monitor/1.1"))
+	ua = fmt.Sprintf("influxdb-client-go/%s (%s; %s) Monitor/1.1", Version, runtime.GOOS, runtime.GOARCH)
+	assert.False(t, strings.Contains(sb.String(), "Application name is not set"))
+	up, err = c.Ping(context.Background())
+	require.NoError(t, err)
+	assert.True(t, up)
+
+	err = c.WriteAPIBlocking("o", "b").WriteRecord(context.Background(), "a,a=a a=1i")
+	assert.NoError(t, err)
+	c.Close()
+
+	ua = "Monitor/1.1"
+	opts := DefaultOptions()
+	opts.HTTPOptions().SetHTTPDoer(&doer{
+		userAgent: ua,
+		doer:      http.DefaultClient,
+	})
+
+	//Create client with custom user agent setter
+	c = NewClientWithOptions(server.URL, "x", opts)
+	up, err = c.Ping(context.Background())
+	require.NoError(t, err)
+	assert.True(t, up)
+
+	err = c.WriteAPIBlocking("o", "b").WriteRecord(context.Background(), "a,a=a a=1i")
+	assert.NoError(t, err)
+	c.Close()
 }
 
 func TestServerError429(t *testing.T) {

example_ua_set_test.go

@@ -0,0 +1,54 @@
+// Copyright 2022 InfluxData, Inc. All rights reserved.
+// Use of this source code is governed by MIT
+// license that can be found in the LICENSE file.
+
+package influxdb2_test
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/influxdata/influxdb-client-go/v2"
+	ihttp "github.com/influxdata/influxdb-client-go/v2/api/http"
+)
+
+// UserAgentSetter is the implementation of Doer interface for setting User-Agent header
+type UserAgentSetter struct {
+	UserAgent   string
+	RequestDoer ihttp.Doer
+}
+
+// Do fulfills the Doer interface
+func (u *UserAgentSetter) Do(req *http.Request) (*http.Response, error) {
+	// Set User-Agent header to request
+	req.Header.Set("User-Agent", u.UserAgent)
+	// Call original Doer to proceed with request
+	return u.RequestDoer.Do(req)
+}
+
+func ExampleClient_customUserAgentHeader() {
+	// Set custom Doer to HTTPOptions
+	opts := influxdb2.DefaultOptions()
+	opts.HTTPOptions().SetHTTPDoer(&UserAgentSetter{
+		UserAgent:   "NetMonitor/1.1",
+		RequestDoer: http.DefaultClient,
+	})
+
+	//Create client with customized options
+	client := influxdb2.NewClientWithOptions("http://localhost:8086", "my-token", opts)
+
+	// Always close client at the end
+	defer client.Close()
+
+	// Issue a call with custom User-Agent header
+	resp, err := client.Ping(context.Background())
+	if err != nil {
+		panic(err)
+	}
+	if resp {
+		fmt.Println("Server is up")
+	} else {
+		fmt.Println("Server is down")
+	}
+}

internal/http/userAgent.go

@@ -5,5 +5,17 @@
 // Package http hold internal HTTP related stuff
 package http
 
-// UserAgent keeps once created User-Agent string
-var UserAgent string
+import (
+	"fmt"
+)
+
+// UserAgentBase keeps once created base User-Agent string
+var UserAgentBase string
+
+// FormatUserAgent creates User-Agent header value for application name
+func FormatUserAgent(appName string) string {
+	if appName != "" {
+		return fmt.Sprintf("%s %s", UserAgentBase, appName)
+	}
+	return UserAgentBase
+}

options.go

@@ -219,6 +219,17 @@ func (o *Options) AddDefaultTag(key, value string) *Options {
 	return o
 }
 
+// ApplicationName returns application name used in the User-Agent HTTP header
+func (o *Options) ApplicationName() string {
+	return o.HTTPOptions().ApplicationName()
+}
+
+// SetApplicationName sets an application name to the User-Agent HTTP header
+func (o *Options) SetApplicationName(appName string) *Options {
+	o.HTTPOptions().SetApplicationName(appName)
+	return o
+}
+
 // DefaultOptions returns Options object with default values
 func DefaultOptions() *Options {
 	return &Options{logLevel: 0, writeOptions: write.DefaultOptions(), httpOptions: http.DefaultOptions()}

options_test.go

@@ -33,6 +33,7 @@ func TestDefaultOptions(t *testing.T) {
 	assert.EqualValues(t, (*tls.Config)(nil), opts.TLSConfig())
 	assert.EqualValues(t, 20, opts.HTTPRequestTimeout())
 	assert.EqualValues(t, 0, opts.LogLevel())
+	assert.EqualValues(t, "", opts.ApplicationName())
 }
 
 func TestSettingsOptions(t *testing.T) {
@@ -53,7 +54,8 @@ func TestSettingsOptions(t *testing.T) {
 		SetTLSConfig(tlsConfig).
 		SetHTTPRequestTimeout(50).
 		SetLogLevel(3).
-		AddDefaultTag("t", "a")
+		AddDefaultTag("t", "a").
+		SetApplicationName("Monitor/1.1")
 	assert.EqualValues(t, 5, opts.BatchSize())
 	assert.EqualValues(t, true, opts.UseGZip())
 	assert.EqualValues(t, 5_000, opts.FlushInterval())
@@ -66,6 +68,7 @@ func TestSettingsOptions(t *testing.T) {
 	assert.EqualValues(t, 5, opts.ExponentialBase())
 	assert.EqualValues(t, tlsConfig, opts.TLSConfig())
 	assert.EqualValues(t, 50, opts.HTTPRequestTimeout())
+	assert.EqualValues(t, "Monitor/1.1", opts.ApplicationName())
 	if client := opts.HTTPClient(); assert.NotNil(t, client) {
 		assert.EqualValues(t, 50*time.Second, client.Timeout)
 		assert.Equal(t, tlsConfig, client.Transport.(*http.Transport).TLSClientConfig)

version.go

@@ -17,5 +17,5 @@ const (
 )
 
 func init() {
-	http.UserAgent = fmt.Sprintf("influxdb-client-go/%s  (%s; %s)", Version, runtime.GOOS, runtime.GOARCH)
+	http.UserAgentBase = fmt.Sprintf("influxdb-client-go/%s (%s; %s)", Version, runtime.GOOS, runtime.GOARCH)
 }